Alkenyl ester – functional resin – linear polyorganosiloxane block copolymer, composition containing the copolymer, and methods for their preparation and use

Abstract

A resin – linear polyorganosiloxane block copolymer and methods for its preparation and use are provided. The resin – linear polyorganosiloxane block copolymer is useful in both thermally curable compositions and UV curable compositions. The compositions are useful for preparing encapsulants for LEDs.

Description

ALKENYL ESTER - FUNCTIONAL RESIN - LINEAR POLYORGANOSILOXANE BLOCK COPOLYMER, COMPOSITION CONTAINING THE COPOLYMER, AND METHODS FOR THEIR PREPARATION AND USECROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 555629 filed on February 20, 2024 under 35 U.S.C. §119 (e). U.S. Provisional Patent Application Serial No. 63 / 555629 is hereby incorporated by reference.FIELD

[0002] An alkenyl ester - functional resin - linear polyorganosiloxane block copolymer and methods for its preparation and use are provided. A curable composition containing the alkenyl ester - functional resin - linear polyorganosiloxane copolymer is useful for forming an encapsulant film.INTRODUCTION

[0003] Light emitting diode (LED) enabled opportunities like mini and micro LED arrays for displays and automotive applications require encapsulant films that can be efficiently cured by heat and / or UV without compromising the long-term stability and optical quality of the light extraction. Specifically, materials are required with high performance such as high optical transmission, high thermal and photothermal stability, strong adhesion, and good mechanical properties. Epoxy based resins have been considered as candidates because of their advantages including good optical clarity, high mechanical strength, strong adhesion and fast cure, but epoxy based resins are limited by their poor thermal and photo / photothermal stability and discoloration. Silicone materials have been broadly applied in LED packaging because of their excellent thermal and photothermal stability, however some of their limitations may restrict the applications, such as weak adhesion and high gas permeability because of their highly flexible siloxane backbone.

[0004] Hydrosilylation or condensation curable silicones have been proposed for LED encapsulation applications as disclosed, for example, in US Patent 9045668 to Horstman, et al. and US Patent 9705056 to Amako, et al., because they may show high transparency, excellent thermal and / or photothermal stability and / or high toughness. However, these silicones may be limited as to which cure systems can be used. Condensation cure systems can generate water and / or alcohol as by products, which may be detrimental to (opto)electronic devices, such as LEDs.SUMMARY

[0005] An alkenyl ester - functional resin - linear polyorganosiloxane block copolymer andmethods for preparation and use of the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer are provided. A curable composition comprising the alkenyl ester - functional resin - linear polyorganosiloxane copolymer and a catalyst can be cured by exposure to heat or UV radiation. The cured product of the composition may be useful as an encapsulant.DETAILED DESCRIPTION

[0006] The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer, introduced above, comprises linear blocks and non - linear blocks. Each linear block comprises 10 to 400 disiloxy units of formula (R22SiO2 / 2), wherein each R2is an independently selected monovalent hydrocarbyl group of 1 to 30 carbon atoms. Each non - linear block has a molecular weight of at least 500 g / mol. The non - linear blocks comprise trisiloxy units and hydrolyzable groups; and the non - linear blocks further comprise alkenyl ester - functional groups bonded to silicon atoms. At least 30 mol % of the non - linear blocks may be crosslinked with each other, and each linear block is linked to at least one non - linear block. The copolymer may have a Mw of at least 20,000 g / mol measured by GPC according to the test method described below in the EXAMPLES.

[0007] Linear polyorganosiloxanes typically comprise mostly D units, which results in polydiorganosiloxanes that are fluids of varying viscosity, depending on the DP, indicated by the number of D units in the polydiorganosiloxanes. Linear polydiorganosiloxanes typically have Tg lower than 25 °C, alternatively lower than 0 °C, and alternatively lower than -20 °C.

[0008] “Resin” polysiloxane results when a majority of the siloxy units are T, Q, or both units. When T siloxy units are predominant, the resulting polysiloxane can be referred to as a “silsesquioxane resin”. When Q units are predominant, the resulting polysiloxane can be referred to as a silicate. Increasing the amount of T and / or Q siloxy units (relative to amount of M and / or D units) typically results in polysiloxanes having increasing hardness and / or glass like properties. “Resin” polysiloxanes thus have higher Tg values than linear polydiorganosiloxanes, for example resin polysiloxanes often have Tg values greater than 30 °C, alternatively greater than 40 °C, and alternatively greater than 50 °C. Alternatively up to 100 °C, alternatively up to 80 °C, alternatively up to 70 °C, and alternatively 50 °C to 100 °C.

[0009] As used herein, “resin - linear polyorganosiloxane block copolymer” refers to polyorganosiloxanes containing polydiorganosiloxane blocks comprising, alternatively consisting essentially of, alternatively consisting of, D units in combination with resin blocks comprising T units. The resin - linear polyorganosiloxane block copolymer is a block copolymer (not a random copolymer). D units are bonded together to form polymeric polydiorganosiloxane chains having 10 to 400 D units, referred to herein as linear blocks. The Tunits are primarily bonded to each other to form branched polymeric chains, and these are included in the non - linear blocks. A significant number of these non - linear blocks may aggregate to form nano-domains when solid forms of the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer are provided. The disiloxy units of formula (R22SiO2 / 2) that are arranged in linear blocks have an average of 10 to 400 units of formula (R22SiO2 / 2) per linear block. Alternatively, each linear block may have an average of at least 10, alternatively at least 50, alternatively at least 100, alternatively at least 150, and alternatively at least 200 disiloxy units; while at the same time each linear block may have up to 400, alternatively up to 300, and alternatively up to 200, disiloxy units per linear block. Alternatively, each linear block may have 100 to 150 disiloxy units, alternatively 115 to 125 disiloxy units, alternatively 90 to 170 disiloxy units. The linear blocks are covalently bonded to the non - linear blocks.

[0010] The trisiloxy units are arranged in the non - linear blocks. The non - linear blocks each have a molecular weight of at least 500 g / mol, alternatively 500 g / mol to 4,000 g / mol per block. Alternatively, each non - linear block may have a Mn of at least 500 g / mol, alternatively at least 1,000 g / mol, alternatively at least 1,500 g / mol; while at the same time each non - linear block may have a Mn of up to 4,000 g / mol, alternatively up to 3,000 g / mol; alternatively up to 2,500 g / mol; alternatively up to 2,000 g / mol; and alternatively up to 1,500 g / mol.

[0011] The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may further comprise hydrolyzable groups in the non - linear blocks. The hydrolyzable groups may have formula (ZO1 / 2), wherein each Z is independently selected from H or a monovalent hydrocarbyl group of 1 to 30 carbon atoms. Alternatively, the monovalent hydrocarbyl group for Z may be an alkyl group, such as an alkyl group of 1 to 6 carbon atoms, alternatively 1 to 4 carbon atoms, alternatively 1 to 2 carbon atoms, and alternatively methyl. Alternatively, each Z may be H. The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may comprise up to 50 mol % of the hydrolyzable groups, alternatively at least 0.5 mol%, alternatively at least 1 mol%, alternatively at least 5 mol %, alternatively at least 10 mol%, and alternatively at least 15 mol%; while at the same time the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may comprise up to 50 mol %, alternatively up to 35 mol %, alternatively up to 30 mol%, alternatively up to 25 mol%, and alternatively up to 20 mol % of the hydrolyzable groups.

[0012] The hydrolyzable groups may allow the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer to further react or cure or to crosslink. Crosslinking of the non - linear blocks may be accomplished via a variety of chemical mechanisms and / or moieties. For example, crosslinking of the non - linear blocks within the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may result from condensation of residual silanoland / or alkoxy groups present in the non - linear blocks. At least 30% of the non - linear blocks in the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may be crosslinked with each other, alternatively at least 40%, alternatively at least 50%, alternatively at least 60%, alternatively at least 70%, and alternatively at least 80%. Alternatively, 30% to 80% of the non - linear blocks may be crosslinked with each other, alternatively 30% to 70%, alternatively 30% to 60%, alternatively 30% to 40%, and alternatively 30% to 40% of the non - linear blocks are crosslinked with each other.

[0013] The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may have a Mw of 20,000 g / mol to 500,000 g / mol. Alternatively, the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may have a Mw of at least 20,000 g / mol, alternatively at least 40,000 g / mol, alternatively at least 50,000 g / mol, alternatively at least 60,000 g / mol, alternatively at least 70,000 g / mol, and alternatively at least 80,000 g / mol; while at the same time Mw may be up to 500,000 g / mol, alternatively up to 450,000 g / mol, alternatively up to 400,000 g / mol, alternatively up to 350,000 g / mol, alternatively up to 300,000 g / mol; alternatively up to 250,000 g / mol; alternatively up to 200,000 g / mol; alternatively up to 150,000 g / mol and alternatively up to 100,000 g / mol. Alternatively, the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may have a Mn of 15,000 to 50,000 g / mol. Alternatively, the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may have a Mw of 25,000 g / mol to 400,000 g / mol, alternatively 30,000 g / mol to 300,000 g / mol, alternatively 35,000 g / mol to 200,000 g / mol, alternatively 40,000 g / mol to 100,000 g / mol, alternatively 45,000 g / mol to 75,000 g / mol, and alternatively 49,000 to 74,000 g / mol. Alternatively, the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may have Mn of at least 15,000 g / mol, alternatively at least 20,000 g / mol; while at the same time Mn may be up to 50,000 g / mol, alternatively up to 30,00 g / mol, alternatively up to 25,000 g / mol. Mw and Mn may be measured by GPC, using the test method provided in the EXAMPLES, below.

[0014] The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may have, per molecule, at least one alkenyl ester group of formula R4, as described and exemplified below. Each alkenyl ester group is covalently bonded to a silicon atom. The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may have an alkenyl ester group content of 0.5 mol % to 5 mol %, alternatively 1 mol % to 4 mol %, and alternatively 2 mol % to 3 mol %. The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may be free of silicone polyether moieties.

[0015] The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may be isolated in a solid form, for example, by casting a film of a solution of the alkenyl ester -functional resin - linear polyorganosiloxane block copolymer in an organic solvent (e.g., benzene, toluene, xylene, or a combination thereof) and allowing the solvent to evaporate. The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may be provided in a solution in an organic solvent in an amount of 50% to 80%, alternatively 60% to 80%, copolymer solids with the balance being organic solvent in the solution. The solution may be cast as a film and then dried to remove the solvent and form a solid, and the non - linear blocks may further aggregate together to form nano - domains. As used herein, “predominately aggregated” means the majority of the non - linear blocks are found in certain regions of the solid composition, referred to herein as “nano - domains”. The nano - domains refer to phase regions within the solid alkenyl ester - functional resin - linear polyorganosiloxane block copolymer that are phase separated and possess at least one dimension sized from 1 nm to 100 nm. The nano - domains may vary in shape, providing at least one dimension of the nano - domains is sized from 1 to 100 nm. The nano - domains may be regularly or irregularly shaped, alternatively spherical, tubular, or lamellar shaped. Alternatively, the solid alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may contain a first phase and an incompatible second phase, the first phase containing predominantly the linear block and the second phase containing predominantly the non - linear block, the non - linear blocks being sufficiently aggregated into nano - domains that are incompatible with the first phase.

[0016] Alternatively, the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may comprise unit Formula (B) as follows(ZOi / 2)s(B).In unit formula (B), each R1is an independently selected monovalent hydrocarbyl group of 1 to 30 carbon atoms; each R2is the independently selected monovalent hydrocarbyl group of 1 to 30 carbon atoms as introduced above; each D1is an independently selected divalent hydrocarbyl group of 2 to 30 carbon atoms; each R3is independently selected from an alkenyl group of 2 to 30 carbon atoms or an aryl group of 6 to 30 carbon atoms; each R4is an alkenyl ester - functional group; each Z is independently selected from H or a monovalent hydrocarbyl group of 1 to 30 carbon atoms as described above; subscripts m, n, o, p, q, and r represent mole fractions of each siloxy unit in the unit formula, and have values such that 0 < m < 0.1; 0.3 < n < 0.8;0.035 < o < 0.8; 0.3 < (n + o) < 0.8; 0.035 < p < 0.8; 0.1 < q < 0.7; and 0.035 < r < 0.285; andsubscript s represents a molar amount of hydrolyzable groups in the copolymer, and subscript f has a value such that 0 < s < 0.5.

[0017] The monovalent hydrocarbyl group for R1and / or R2may be an alkyl group or an aryl group. Suitable alkyl groups have 1 to 30 carbon atoms and may be linear, branched, cyclic or combinations of two or more thereof. Examples of suitable alkyl groups include methyl, ethyl, propyl (including n-propyl and / or isopropyl), butyl (including n-butyl, tert-butyl, sec-butyl, and / or isobutyl); pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and octadecyl (and branched isomers having 5 to 18 carbon atoms), and the alkyl groups are further exemplified by cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Alternatively, the alkyl group may be methyl, ethyl, propyl, butyl, or hexyl; alternatively methyl or ethyl; and alternatively methyl. Suitable aryl groups for R1and / or R2may have 6 to 30 carbon atoms and may be monocyclic or polycyclic, optionally with pendant hydrocarbyl groups. The aryl groups are exemplified by phenyl, tolyl, xylyl, benzyl, naphthyl, anthracenyl, 1-phenyl ethyl, and 2- phenyl ethyl. Alternatively, the aryl group may be monocyclic, such as phenyl, tolyl, or benzyl. Alternatively, the aryl group may be phenyl or naphthyl; alternatively phenyl. Alternatively, each R1may be selected from the group consisting of methyl and phenyl, alternatively methyl. Alternatively, each R2may be selected from the group consisting of methyl and phenyl.

[0018] In unit formula (B), each D1is an independently selected divalent hydrocarbyl group of 2 to 30 carbon atoms. Examples of divalent hydrocarbyl groups for D1include an alkylene group such as ethylene, propylene, butylene, or hexylene; and an arylene group such as phenylene,Alternatively, D1may be an alkylene group such as ethylene.

[0019] In unit formula (B), each R3is independently selected from an alkenyl group of 2 to 30 carbon atoms or an aryl group of 6 to 30 carbon atoms. The aryl group for R3may be as described and exemplified above for R1and R2. The alkenyl group may have terminal alkenyl functionality, e.g. , the alkenyl group for R may have formulasubscript y is 0 to 6. Alternatively, each alkenyl group may be independently selected from the group consisting of vinyl, allyl, and hexenyl; alternatively, vinyl and allyl; alternatively, vinyl;and alternatively, allyl.

[0020] In unit formula (B), each R4is an independently selected alkenyl ester - functional group. Alternatively, each R4may be an independently selected (meth)acryl - functional group, such as a (meth)acryloxyalkyl group. The alkenyl ester - functional group R4may have formula, wherein D2is a divalent hydrocarbyl group of 2 to 30 carbon atoms, and R10is H or an alkyl group of 1 to 6 carbon atoms. Suitable divalent hydrocarbyl groups for D2are as described and exemplified above for D1. Alternatively, D2may be an alkylene group of 2 to 10 carbon atoms, and alternatively D2may be selected from the group consisting of ethylene, propylene, and hexylene; alternatively ethylene and propylene. Alternatively, R10may be selected from H or methyl. Alternatively, R10may be methyl. Alternatively, R4may be selected from an acryloxyalkyl- group or a methacryloxyalkyl- group. Alternatively, R4may be selected from aery loxy methyl, methacryloxymethyl, acryloxypropyl, methacryloxypropyl, acryloxybutyl, or methacryloxybutyl. Alternatively, R4may be selected from acryloxypropyl or methacryloxypropyl.

[0021] In unit formula (B), each Z is independently selected from H or a monovalent hydrocarbyl group of 1 to 30 carbon atoms. Alternatively, the monovalent hydrocarbyl group for Z may be an alkyl group as described above for R1and / or R2, such as an alkyl group of 1 to 6 carbon atoms, alternatively 1 to 4 carbon atoms, alternatively 1 to 2 carbon atoms; alternatively methyl. Alternatively, each Z may be H.

[0022] In unit Formula (B), each of subscripts m, n, o, p, q, and r represent mole fractions of each siloxy unit in the unit formula and subscripts m, n, o, p, q, and r have values such that 0 < m < 0.1; 0.3 < n < 0.8; 0.035 < o < 0.285; 0.3 < (n + o) < 0.8; 0.035 < p < 0.285; 0.1 < q < 0.7; and 0.035 < r < 0.285; and a quantity (m + n + o -i- p -i- q -i- r) = 1. Alternatively, subscript m may have a value such that 0 < m < 0.1, alternatively 0 < m < 0.05, and alternatively 0.01 < m < 0.05. Alternatively, subscript n may have a value such that 0.3 < n < 0.6, alternatively 0.3 < n < 0.5; and alternatively 0.35 < n < 0.65. Alternatively , subscript o may have a value such that 0 < o < 0.15; alternatively 0.01 < o < 0.2; and alternatively 0.035 < o < 0.1. Alternatively, subscript p may have a value such that that 0 < p < 0. 15; alternatively 0.01 < p < 0.2; and alternatively 0.035 < p < 0.1. Alternatively subscript q may have a value such that 0.15 < q < 0.65; alternatively 0.2 < q < 0.6, and alternatively 0.3 < q < 0.5. Alternatively, subscript r may have a value such that 0.035 < r < 0.1; alternatively 0.05 < r < 0.1; alternatively 0.06 < r < 0.08; andalternatively r = 0.7. Subscript s represents a molar amount of hydrolyzable groups in the copolymer, and subscript s has a value such that 0 < s < 0.5; alternatively 0.05 < s < 0.35; and alternatively 0.05 < s < 0.20.

[0023] The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer described above may be prepared by a method comprising: (1) combining, under conditions to effect hydrosilylation reaction, starting materials comprising: (1-1) an alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer; and (1-2) an alkenyl ester - functional silyl hydride compound of formula, wherein each R16is an independently selected monovalent hydrocarbyl group of 1 to 30 carbon atoms, R4is the alkenyl ester - functional group as described and exemplified above, and subscript w is an integer with a value of 0, 1, or 2; and (c2) a hydrosilylation reaction catalyst, as described and exemplified above; and optionally (2) recovering the copolymer from the hydrosilylation reaction product.

[0024] Starting material (1-1) is an alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer that may be prepared by known methods, such as those described in US Patent 9765192 to Horstman, et al., which is hereby incorporated by reference. Any of the alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymers described therein may be used in this method. The alkenyl-, aryl- functional resin - linear copolymer may comprise 0.5 mol% to 5 mol% of alkenyl groups.

[0025] For example, the alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer for starting material (1-1) may comprise: difunctional siloxy units and trifunctional siloxy units, wherein the alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer comprises unit formula (bl - 1 ) (R142SiO2 / 2)t(R15SiO3 / 2)u(ZOi / 2)v, wherein each R14and each R15are independently selected monovalent hydrocarbyl groups of 1 to 30 carbon atoms; each Z is independently selected from the group consisting of a hydrogen atom and a monovalent hydrocarbyl group of 1 to 30 carbon atoms; subscripts t and u represent mole fractions of siloxy units in (1-1) the alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer, and subscripts t and u have values such that 0.4 < t < 0.9 and 0.1 < u < 0.6, and a quantity (t + u) = 1 , subscript v represents a mole fraction of hydrolyzable groups and has a value such that 0 < v < 0.5, wherein the disiloxy units are arranged in linear blocks having an average of 10 to 400 units of formula (R142SiCh / 2) per linear block; and wherein the trisiloxy units of formula (R15SiCh / 2) are arranged in non - linear blocks, wherein each non - linear blockhas a molecular weight of at least 500 g / mol. Each R14may be free of aliphatically unsaturated bonds, e.g., R14may be selected from alkyl or aryl, as described and exemplified above for R1and R2. Alternatively, each R14may be alkyl. Alternatively, each R14may be methyl.

[0026] In starting material (1-1), each R15may be independently selected from alkyl, alkenyl, and aryl; alternatively each R15may be independently selected from alkenyl and aryl. The alkyl group and the aryl group for R15may be as described above for R1and R2. The alkenyl for R15may be as described above for R3. Alternatively, the alkyl group for R15may be methyl. Alternatively, the aryl group for R15may be phenyl or naphthyl, alternatively phenyl. Alternatively, the alkenyl group for R1Smay be vinyl, allyl, or hexenyl; alternatively vinyl or hexenyl; alternatively vinyl or allyl; and alternatively vinyl. In the unit formula above, the balance of instances of R15that are not alkenyl groups may be aryl groups.

[0027] Subscripts t and u represent mole fractions of siloxy units in (1-1) the alkenyl-, aryl- functional resin - linear copolymer, and subscripts t and u have values such that 0.4 < t < 0.9 and 0. 1 < u < 0.6, and a quantity (t + u) = 1. Subscript v represents a mole fraction of hydrolyzable groups and has a value such that 0 < v < 0.5. Alternatively, subscript v may have a value such that 0.05 < v < 0.35, alternatively 0.05 < v < 0.2.

[0028] The alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer is a block copolymer (not a random copolymer). The difunctional units of formula (R142SiO2 / 2) are primarily bonded together to form polymeric polydiorganosiloxane chains having 10 to 400 (R142SiO2 / 2) units, which are linear blocks. The (R15SiO3 / 2) units are primarily bonded to each other to form branched polymeric chains, which are non - linear blocks. A significant number of these non - linear blocks may aggregate to form nano-domains when solid forms of the alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer are provided. The disiloxy units of formula (R142SiO2 / 2) that are arranged in linear blocks have an average of 10 to 400 units of formula (R142SiO2 / 2) per linear block. Alternatively, each linear block may have an average of at least 10, alternatively at least 50, alternatively at least 100, alternatively at least 150, and alternatively at least 200 units of formula (R142SiO2 / 2); while at the same time each linear block may have up to 400, alternatively up to 300, and alternatively up to 200, units of formula (R142SiO2 / 2) per linear block. Alternatively, each linear block may have 100 to 150 (R142SiO2 / 2) units, alternatively 115 to 125 (R142SiO2 / 2) units, alternatively 90 to 170 (R142SiO2 / 2) units. The linear blocks are covalently bonded to the non - linear blocks.

[0029] The (R15SiC>3 / 2) units are arranged in the non - linear blocks. The non - linear blocks each have a molecular weight of at least 500 g / mol, alternatively 500 g / mol to 4,000 g / mol per block. Alternatively, each non - linear block may have a Mn of at least 500 g / mol, alternatively at least 1,000 g / mol, alternatively at least 1,500 g / mol; while at the same time each non - linearblock may have a Mn of up to 4,000 g / mol, alternatively up to 3,000 g / mol; alternatively up to 2,500 g / mol; alternatively up to 2,000 g / mol; and alternatively up to 1,500 g / mol, measured by GPC according to the test method described in the EXAMPLES, below.

[0030] The hydrolyzable groups may allow the alkenyl-, aryl- functional resin - linear copolymer to further react or cure or to crosslink. Crosslinking of the non - linear blocks may be accomplished via a variety of chemical mechanisms and / or moieties. For example, crosslinking of the non - linear blocks within the copolymer may result from condensation of residual silanol and / or alkoxy groups present in the non - linear blocks. At least 30% of the non- linear blocks in the copolymer may be crosslinked with each other, alternatively at least 40%, alternatively at least 50%, alternatively at least 60%, alternatively at least 70%, and alternatively at least 80%. Alternatively, 30% to 80% of the non - linear blocks may be crosslinked with each other, alternatively 30% to 70%, alternatively 30% to 60%, alternatively 30% to 40%, and alternatively 30% to 40% of the non - linear blocks are crosslinked with each other.

[0031] The alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer may have an alkenyl content of 0.5 mol % to 5 mol%, alternatively 1 mol % to 4 mol %, and alternatively 2 mol % to 3 mol%.

[0032] The alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer may have a Mw of 20,000 g / mol to 500,000 g / mol. Alternatively, the copolymer may have a Mw of at least 20,000 g / mol, alternatively at least 40,000 g / mol, alternatively at least 50,000 g / mol, alternatively at least 55,000 g / mol, alternatively at least 60,000 g / mol, and alternatively at least 65,000 g / mol; while at the same time Mw may be up to 500,000 g / mol, alternatively up to 450,000 g / mol, alternatively up to 400,000 g / mol, alternatively up to 350,000 g / mol, alternatively up to 300,000 g / mol; alternatively up to 250,000 g / mol; alternatively up to 200,000 g / mol; alternatively up to 150,000 g / mol and alternatively up to 125,000 g / mol. Alternatively, the alkenyl-, aryl- functional resin - linear copolymer may have a Mn of 15,000 to 50,000 g / mol. Alternatively, the alkenyl-, aryl- functional resin - linear copolymer may have Mn of at least 15,000 g / mol, alternatively at least 20,000 g / mol; while at the same time Mn may be up to 50,000 g / mol, alternatively up to 30,000 g / mol, alternatively up to 25,000 g / mol. Mw and Mn may be measured by GPC using the test method described in the EXAMPLES, below.

[0033] The alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer may be isolated in a solid form, for example, by casting a film of a solution of the alkenyl-, aryl- functional resin - linear copolymer in an organic solvent (e.g., benzene, toluene, xylene, or combinations thereof) and allowing the solvent to evaporate. The alkenyl-, aryl- functional resin- linear polyorganosiloxane block copolymer may be provided in a solution in an organic solvent in an amount of 50% to 80%, alternatively 60% to 80%, copolymer solids with thebalance being organic solvent in the solution. The solution may be cast as a film and then dried to remove the solvent and form a solid, and the non - linear blocks may further aggregate together to form nano - domains, as described above. Alternatively, the solid alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer may contain a first phase and an incompatible second phase, the first phase containing predominantly the linear block and the second phase containing predominantly the non - linear block, the non - linear blocks being sufficiently aggregated into nano - domains that are incompatible with the first phase.

[0034] Starting material (1-2) is an alkenyl ester - functional silyl hydride compound of formula(wherein each R16is an independently selected monovalent hydrocarbyl group of 1 to 30 carbon atoms, R4is the alkenyl ester - functional group as described and exemplified above, and subscript w is an integer with a value of 0, 1, or 2. The monovalent hydrocarbyl group for R16is as described and exemplified above for R1and R2. Alternatively, each R16may be independently selected from the group consisting of an alkyl group and an aryl group. Alternatively, each R16may be an alkyl group. Alternatively, each R16may be methyl. Alkenyl ester - functional silyl hydride compounds of the formula shown above are known in the art and may be made by known methods, such as that described in PCT Patent Publication WO2023023435; EP Patent 3387045B1 corresponding to US Patent 10280265 to Eldred, et al. and US Provisional Patent Application Serial No. 63 / 626088, which are hereby incorporated by reference for the purpose of disclosing alkenyl ester - functional silyl hydride compounds. The amount of starting material (1-2) may be sufficient to provide 3.5 mol% to 15 mol%, based on mole number of starting material (1-1).

[0035] Starting material (c2) is a hydrosilylation reaction catalyst. The hydrosilylation reaction catalyst will promote a reaction between the alkenyl groups and the silicon bonded hydrogen atoms of starting materials (1-1) and (1-2), described above. The hydrosilylation reaction catalyst comprises a platinum group metal. The platinum group metal may be selected from the group consisting of platinum, rhodium, ruthenium, palladium, osmium, and iridium. Alternatively, the platinum group metal may be platinum. The hydrosilylation reaction catalyst may be the platinum group metal or a compound or complex of the platinum group metal. For example, the hydrosilylation reaction catalyst may be a compound such as chloridotris(triphenylphosphane)rhodium(I) (Wilkinson’s Catalyst), a rhodium diphosphine chelate such as [l,2-bis(diphenylphosphino)ethane]dichlorodirhodium or [1,2-bis(diethylphospino)ethane|dichlorodirhodium, chloroplatinic acid (Speier’s Catalyst), chloroplatinic acid hexahydrate, platinum dichloride, or a complex of such a compound with an organopolysiloxane such as l,3-diethenyl-l,l,3,3-tetramethyldisiloxane complexes with platinum (Karstedt’s Catalyst) or Pt(O) complex in tetramethyltetravinylcyclotetrasiloxane (Ashby’s Catalyst). Alternatively, the compound or complex may be microencapsulated in a matrix or coreshell type structure. Hydrosilylation reaction catalysts are known in the art, for example, as described in PCT Patent Application Publication WO2021 / 081822 to Guo, et al. and the references cited therein. Hydrosilylation reaction catalysts are commercially available, for example, SYL-OFF™ 4000 Catalyst and SYL-OFF™ 2700 are available from Dow Silicones Corporation of Midland, Michigan, USA. The amount of hydrosilylation reaction catalyst used in this method depends on various factors including the selection and SiH content of starting material (1-2), the alkenyl content of starting material (1-1) the alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer, and the hydrosilylation reaction conditions, such as temperature, however the amount may be sufficient to provide 0.1 to 5,000 ppm of platinum group metal, alternatively 1 to 1,000 ppm, alternatively 1 to 100 ppm, and alternatively 1 to 10 ppm, based on combined weights of starting materials (1-1) and (1-2).

[0036] A solvent may optionally be included during and / or after step (1) of the method described above to facilitate mixing of the starting materials. The solvent is not critical and may be, for example, an aromatic hydrocarbon exemplified by benzene, toluene, xylene, or a combination thereof.

[0037] In step (1) of the method described above, the starting materials (1-1), (1-2), and (c2), and optionally a solvent to aid mixing, may be combined in a reactor with heating at a temperature of 50 °C to 150 °C, alternatively 90 °C to 110 °C. Typically, (1-1) the alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer used in a molar excess such that the resulting alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may have residual silicon bonded alkenyl groups, and does not contain unreacted SiH.

[0038] In step (2) of the method described above, recovering the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may be performed by any convenient means, such as stripping and / or distillation, optionally with reduced pressure.

[0039] Step (1), and optionally when present step (2), may be performed with heating under anaerobic conditions, e.g., for safe handling of SiH functional starting material. For purposes of this application, “anaerobic” conditions means that no more than 2% oxygen, alternatively less than 2%, is present in the gas in the headspace of a vessel (used to perform the method described herein), or dissolved in the liquid where the reaction to form the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer takes place or where recovering is performed,when step (2) is present. The balance of the gas in the headspace could be an inert gas such as nitrogen or argon. Alternatively, “anaerobic” includes performing one or more method steps under an inert gas sweep in the vessel used to perform step (1) of the method for preparing the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer described herein, alternatively to recover the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer when step (2) is present, or both. Heating under anaerobic conditions may be performed by any convenient means and may be continuous or intermittent. Heating under anaerobic conditions may be performed for at least 1, alternatively at least 2 hours; while at the same time heating under anaerobic conditions may be performed for up to 48, alternatively up to 24, alternatively up to 12, and alternatively up to 9 hours. All or a portion of the heating under anaerobic conditions may be performed during formation of the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer, e.g., during step (1). Alternatively, all or a portion of the heating under anaerobic conditions may be performed during recovery of the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer, e.g., during step (2), when step (2) is present.

[0040] When heating under anaerobic conditions, a (meth)acrylate polymerization inhibitor (inhibitor) may be used to prevent or minimize polymerization of the alkenyl ester - functional groups. The inhibitor used herein comprises a manganese ion source and a phenolic compound. The manganese ion source used herein may be a manganese (III) compound or a manganese (II) compound. Alternatively, the manganese ion source may be a manganese (II) compound. Suitable manganese compounds include manganese (II) acetate, manganese (II) nitrite, manganese (II) propionate, manganese (II) oxide, manganese (II) hydroxide, manganese (II) chloride, manganese (II) phosphate, manganese (II) perchlorate, hydrates thereof (e.g., manganese (II) tetrahydrate) and combinations thereof. Alternatively, the manganese ion source may comprise manganese (II) acetate or manganese (II) tetrahydrate, or a combination thereof. Suitable manganese ion sources are commercially available from Millipore Sigma of St. Louis, Missouri, USA, Fisher Scientific of Waltham, Massachusetts, USA, and City Chemical LLC of Connecticut, USA. The amount of manganese ion source depends on various factors including the selections and amounts of starting materials used in the method, and the time and temperature for heating. However the amount of manganese ion source may be 0.1 ppm to 5,000 ppm, alternatively 0.1 ppm to 1,000 ppm, based on combined weights of all starting materials used in the methods described herein to make the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer, excluding solvent, if used. Alternatively, the amount of the manganese ion source may be > 0 ppm, alternatively at least 0.1 ppm, alternatively at least 0.5 ppm, alternatively at least 1 ppm, alternatively at least 1.5 ppm; while atthe same time, the amount of manganese ion source may be up to 5,000 ppm, alternatively up to 1,000 ppm, alternatively up to 100 ppm, alternatively up to 10 ppm, alternatively up to 5 ppm, alternatively up to 4 ppm, and alternatively up to 3 ppm, and alternatively up to 2 ppm, on the same basis.

[0041] The phenolic compound used herein has one or more phenolic groups per molecule. Suitable phenolic compounds include hydroquinone (HQ), dihydroxybenzene (catechol), resorcinol, dihydroxyxylene, methoxyphenols such as guaiacol, p-methoxyphenol (also called methyl ether of hydroquinone or MeHQ), tert-butyl hydroquinone (tBuHQ), pyrogallol, methylpyrogallol, cresol, phenol, xylenols, and combinations thereof. Alternatively, the phenolic compound may be selected from the group consisting of HQ, MeHQ, tBuHQ, and a combination of two or more thereof. Suitable phenolic compounds are commercially available, e.g., from Millipore Sigma of St. Louis, Missouri, USA. The amount of phenolic compound source depends on various factors including the selections and amounts of starting materials used to make the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer, however the amount may be 5 ppm to 5,000 ppm based on combined weights of all starting materials used in the methods described herein to make the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer, excluding solvent, if used. Alternatively, the amount of the phenolic compound may be at least 5 ppm, alternatively at least 50 ppm, alternatively at least 100 ppm, alternatively at least 150 ppm; while at the same time, the amount of phenolic compound may be up to 500 ppm, alternatively up to 400 ppm, alternatively up to 350 ppm, and alternatively up to 320 ppm, on the same basis.

[0042] One skilled in the art would recognize that the method described above may be used to prepare the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer of unit Formula (B), described above. Alternatively, the method described above may be used to prepare an alkenyl ester - functional resin - linear polyorganosiloxane block copolymer with a different unit formula, e.g., by varying appropriate starting materials. For example, when a different alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer for starting material (1-1) is used (e.g., such as a DV1modified resin linear block copolymer or an MV1modified resin linear block copolymer, as described in US Patent 9765192 in addition to, or instead of unit formula (bl-1)), an alkenyl - ester functional resin - linear polyorganosiloxane block copolymer with a different unit formula than unit Formula (B) above may be produced.

[0043] Alternatively, the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may comprise unit Formula (A), as follows:and e represent mole fractions of each siloxy unit in the unit formula, and have values such that 0 < a < 0.1 ; 0.3 < b < 0.8; 0 < c < 0.2; 0.3 < (b + c) < 0.8; 0. 1 < d < 0.7; 0.035 < e < 0.285; subscript f represents a molar amount of hydrolyzable groups in the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer, and subscript f has a value such that 0 < f < 0.5. Alternatively, subscript a may have a value such that 0 < a < 0.1, alternatively 0.05 < a < 0.1, and alternatively 0.07 < a < 0.09. Alternatively, subscript b may have a value such that 0.35 < b < 0.75, alternatively 0.4 < b < 0.7 ; and alternatively 0.45 < b < 0.65. Alternatively , subscript c may have a value such that 0 < c < 0.15; alternatively 0.01 < c < 0.2. Alternatively subscript d may have a value such that 0.15 < d < 0.65; alternatively 0.2 < d < 0.6.Alternatively, subscript e may have a value such that 0.035 < e < 0. 1; alternatively 0.05 < e < 0.1 ; alternatively 0.06 < e < 0.08; and alternatively e = 0.7. Subscript f has a value such that 0 < f < 0.5; alternatively 0.05 < f < 0.35; and alternatively 0.05 < f < 0.20.

[0044] The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer of unit formula (A) described above may be prepared by a method comprising:(Al) combining, under conditions to effect hydrolysis reaction, starting materials comprising:(al-1) an aryltrialkoxysilane of formula R6Si(OR5)3, where R6is an aryl group of 6 to 30 carbon atoms, and each Rsis an independently selected alkyl group of 1 to 6 carbon atoms;(al-2) an alkenyl ester - functional trialkoxysilane of formula R4Si(OR5)3, wherein R4is the alkenyl ester - functional group described and exemplified above, and each R5is the independently selected alkyl group of 1 to 6 carbon atoms;(a 1-3) a bis-alkenyl-terminated diorganosiloxane oligomer of unit formula (R7R12SiOi / 2)2(R22SiO2 / 2)g, where R1and R2are the monovalent hydrocarbyl groups of 1 to 30 carbon atoms as described above; subscript g represents an average number of disiloxy units per molecule, and subscript g is an integer with value such that g > 0; and each R7is an independently selected alkenyl group of 2 to 30 carbon atoms; and(a 1-4) water; in the presence of (cl) an acid catalyst, thereby forming a hydrolysis productcomprising an aryl-, alkenyl ester-, alkenyl- functional silsesquioxane (MT) resin; and optionally adding a solvent to the hydrolysis product formed in step (Al); optionally neutralizing (cl) the acid catalyst after step (Al);(A2) combining, under conditions to effect hydrosilylation reaction, starting materials comprising(a) the aryl-, alkenyl ester-, alkenyl- functional silsesquioxane resin prepared in step (Al),(a2-l) a linear polyorganohydrogensiloxane of unit formula (R12HSiOi / 2)2(R22SiO2 / 2)h, where each R1and each R2are the independently selected monovalent hydrocarbyl groups of 1 to 30 carbon atoms, subscript h represents an average number of disiloxy units per molecule, and subscript h is an integer with a value of 8 to 398; and(a2-2) an organohydrogensiloxane crosslinker; in the presence of (c2) a hydrosilylation reaction catalyst, thereby forming a hydrosilylation reaction product comprising the copolymer; and optionally (A3) recovering the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer from the hydrosilylation reaction product.

[0045] Starting material (a 1-1) used in the method above is an aryltrialkoxysilane of formula R6Si(OR5)3, where R6is an aryl group of 6 to 30 carbon atoms, and each R5is an independently selected alkyl group of 1 to 6 carbon atoms. Suitable aryl groups for R6are as described and exemplified above. Alternatively, R6may be selected from phenyl or naphthyl, alternatively phenyl. R5is an alkyl group of 1 to 6 carbon atoms, alternatively 1 to 4 carbon atoms, and alternatively 1 to 2 carbon atoms. Alternatively, each R5may be methyl. Examples of suitable aryltrialkoxysilanes include phenyltrimethoxysilane (CAS No. 2996-92-1), phenyltriethoxysilane (CAS No. 780-69-8), and naphthyltriethoxysilane (CAS No. 17938-06-6), all of which are commercially available from sources such as Gelest, Inc. of Morrisville, Pennsylvania, USA and Sigma - Aldrich Inc. of St. Louis, Missouri, USA.

[0046] Starting material (a 1-2) is an alkenyl ester - functional trialkoxysilane of formula R4Si(OR5)3, wherein R4is the alkenyl ester - functional group described and exemplified above, and each R5is the independently selected alkyl group of 1 to 6 carbon atoms as described and exemplified above. Examples of alkenyl ester - functional trialkoxysilanes include (meth)acryl - functional trialkoxysilanes such as methacryloxypropyltrimethoxysilane (CAS No. 2530-85- 0), methacryloxypropyltriethoxysilane (CAS No. 21142-29-0), and methacryloxymethyltrimethoxysilane (CAS No. 54586-78-6) all of which are commercially available from sources such as Gelest, Inc, and acryloxypropyltrimethoxysilane (CAS No. 4369-14-6), which is commercially available from OSi Holding Limited. The amount of (al-2) the alkenyl ester - functional trialkoxysilane used may be 3 mol % to 20 mol % based on amounts of starting materials (al-1), (al-2), and (al -3), combined.

[0047] Starting material (al-3) is a bis-alkenyl-terminated diorganosiloxane oligomer of unit formula (R7R12SiOi / 2)2(R22SiO2 / 2)g, where R1and R2are the monovalent hydrocarbyl groups of 1 to 30 carbon atoms as described above; subscript g represents an average number of disiloxy units per molecule, and subscript g is an integer with value such that 9 > g > 0; and each R7is an independently selected alkenyl group of 2 to 30 carbon atoms. The alkenyl group for R7may be as described and exemplified above for R3. Alternatively, R7may be selected from the group consisting of vinyl, allyl, or hexenyl; alternatively vinyl and hexenyl; alternatively vinyl. Subscript g may be 0, alternatively at least 1, alternatively at least 2, alternatively at least 3, alternatively at least 4; while at the same time, g may be up to 9, alternatively up to 8, alternatively up to 7, alternatively up to 6, and alternatively up to 5. Alternatively, R1and R2may be alkyl groups, alternatively methyl. Examples of oligomers suitable for use as starting material (al-3) include l,3-divinyl-l,l,3,3-tetramethyldisiloxane (CAS No. 2627-95-4) and 1,5- divinyl-l,l,3,3,5,5-hexamethyltrisiloxane (CAS No. 136777-27-0) both of which are commercially available from sources such as Gelest, Inc. The amount of (al-3) the bis-alkenyl- terminated diorganosiloxane oligomer used may be 5 mol % to 10 mol % based on amounts of starting materials (al-1), (al-2), and (al-3), combined.

[0048] Starting material (al-4) is water. The water is not generally limited, and may be utilized neat (i.e., absent any carrier vehicles and / or solvents), and / or pure (i.e., free from, or substantially free from, minerals and / or other impurities). For example, the water may be processed or unprocessed prior to the hydrolysis reaction. Examples of processes that may be used for purifying the water include reverse osmosis, distilling, filtering, deionizing, and combinations of two or more thereof, such that the water may be deionized, distilled, and / or filtered. Alternatively, the water may be unprocessed (e.g. may be tap water, i.e., provided by a municipal water system or well water, used without further purification). Alternatively, the water may be purified before use in the method. Alternatively, the water may be utilized as a mixture (e.g. solution or suspension) comprising a carrier vehicle and / or solvent, such as any of those listed herein for solubilizing the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer. Water may be added in an excess amount sufficient to hydrolyze starting materials (al-1) and (al-2) and to facilitate removal with alcohol (e.g., methanol) generated as a side product. The amount of water may be sufficient to provide a molar ratio of water to silicon atoms from starting materials (al-1), (al-2), and (al-3) of 2:1 to 3:1.

[0049] Starting material (cl) is a catalyst capable of forming a hydrolysis product of startingmaterials (al - 1 ), (a 1-2), (al-3), and (al-4). Starting material (cl) may be an acid catalyst, such as a carboxylic acid exemplified by acetic acid, ethanoic acid, propionic acid, octanoic acid, decanoic acid, lauric acid, lactic acid, fluoroacetic acid, and 4,4,4-trifluorobutanoic acid; Bronsted acids Lewis acids such as HC1, acidic phosphoric esters, or a sulphonic acid such as trifluoromethane sulfonic acid. Suitable acids are known in the art and are commercially available. The amount of acid catalyst depends on various factors including the species selected and the species and amounts of starting materials (al- 1), (al-2), (al-3) and the hydrolysis reaction conditions, such as temperature. However, the amount of acid catalyst may be, for example 100 to 1,000 ppm based on weights of starting materials (al-1) and (al-3) combined. Alternatively, the amount of acid catalyst may be 200 ppm to 900 ppm, alternatively 250 ppm to 750 ppm, alternatively 500 ppm, on the same basis.

[0050] Step (Al) may be performed by any convenient means such as mixing optionally with heating. For example, starting materials (al-1), (al-2), (al-3) and (cl) may be combined in a reactor with mixing and heating to a temperature of 50 °C to < 100 °C. Starting material (al-4) the water may be added slowly over time, either continuously or intermittently in two or more aliquots. The resulting mixture may then be heated, optionally with stirring for an additional time period such as 1 hour to 12 hours, alternatively 2 hours to 4 hours, and alternatively 3 hours.

[0051] The method above optionally comprises neutralizing (cl) the acid catalyst during or after step (Al). Neutralizing may be performed by combining (e.g., by simple mixing) a neutralizing agent with the hydrolysis product formed in step (Al). The neutralizing agent is not critical and may be, for example, sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium carbonate, or potassium hydroxide. The amount of neutralizing agent depends on various factors including the type and amount of catalyst used in step (Al), however, the amount of neutralizing agent may be, for example 500 ppm to 2,000 ppm based on weight of the aryl-, alkenyl ester-, alkenyl- functional silsesquioxane resin to be produced in step (Al). The neutralizing agent may be removed by filtration after neutralizing is complete, e.g., before or after step (A2).

[0052] A solvent may optionally be included during and / or after step (Al) and / or step (A2) of the method described above to facilitate mixing of the starting materials and the aryl-, alkenyl ester-, alkenyl- functional silsesquioxane resin produced in step (Al). The solvent is not critical and may be, for example, an aromatic hydrocarbon exemplified by benzene, toluene, xylene, or a combination thereof.

[0053] Alternatively, in step (Al), starting materials (al-1) the aryltrialkoxysilane, (al-3) the bis-alkenyl-terminated diorganosiloxane oligomer, (cl) the catalyst, and (al-4) the water may becombined and heated, optionally with solvent. Thereafter, the neutralizing agent described above may be added, for example, when a strong acid catalyst such as trifluoromethane sulfonic acid is used for starting material (c2). The neutralizing agent may be a strong base, such as KOH. In this method, (al -2) the alkenyl ester - functional trialkoxysilane may then be added, and additional water may be added, with heating. Without wishing to be bound by theory, it is thought that the strong acid catalyst may be neutralized and thereby prevented from catalyzing a reaction of the alkenyl ester moiety of starting material (al -2). And, when a molar excess of the strong base is used, this may function as a catalyst to react starting material (al -2) with the reaction product described above. Thereafter, step (A2) of the method may be performed.

[0054] In step (A2) of the method, the aryl-, alkenyl ester-, alkenyl- functional silsesquioxane resin prepared in step (Al) (which silsesquioxane resin will form the non - linear block of the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer described above), is combined with additional starting materials under conditions to effect hydrosilylation reaction to bond the linear block to the non - linear block. The block with subscript c, shown above in unit Formula (A) forms via the hydrosilylation reaction in step (A2) (i.e., of the alkenyl group from the aryl-, alkenyl ester-, alkenyl- functional silsesquioxane (e.g., MV1T) resin formed in step (Al) with a silicon bonded hydrogen atom of starting material (a2-l) and / or (a2-2) in step (A2) of the method described above). Hydrosilylation may be performed by any convenient means, such as heating under anaerobic conditions. The hydrosilylation may be performed in the same reactor as step (Al) or a different reactor.

[0055] Starting material (a2-l) used in step (A2) of the method described above is a linear polyorganohydrogensiloxane that may have unit formula (R12HSiOi / 2)2(R22SiO2 / 2)h, where each R1and each R2are the independently selected monovalent hydrocarbyl groups of 1 to 30 carbon atoms, subscript h represents an average number of disiloxy units per molecule, and subscript h is an integer with a value of 8 to 398. Alternatively, in this unit formula each R1may be alkyl, alternatively methyl. Alternatively, each R2may be alkyl or aryl; alternatively methyl or phenyl. Alternatively, subscript h may have a value of at least 8, alternatively at least 10, alternatively at least 20, alternatively at least 48, alternatively at least 98, alternatively at least 148, alternatively at least 198; while at the same time, subscript h may be up to 398, alternatively up to 298, alternatively up to 198. Alternatively, subscript h may be 8 to 298, alternatively 23 to 224, alternatively 48 to 198, alternatively 73 to 148, alternatively 73 to 123, and alternatively h = 97. Starting material (a2- 1 ) may be used to form the linear blocks of the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer. Examples of suitable linear polyorganohydrogensiloxanes suitable as starting material (a2-l) are exemplified by bis- dimethylhydridosiloxy-terminated polydimethylsiloxanes with varying degrees ofpolymerization, as described above. Linear polyorganohydrogensiloxanes suitable as starting material (a2-l) are commercially available, such as those available from Gelest, Inc., for example, hydride terminated polydimethylsiloxanes with product codes DMS-H03, DMS-H05, DMS-H11, DMS-H21, DMS-H25, DMS-H31, or DMS-H41. Methods of preparing linear polyorganohydrogensiloxanes suitable for use herein, such as hydrolysis and condensation of organohalosilanes, are well known in the art, as exemplified in: US Patent 3957713 to Jeram et al. and US Patent 4329273 to Hardman, et al.

[0056] Starting material (a2-2) is an organohydrogensiloxane crosslinker that crosslinks non - linear blocks of the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer, as described above. This crosslinker may comprise an organohydrogensiloxane comprising two or more siloxane units selected from, HR^SiOio, R^SiOi / , HR2SiO2 / 2, R22SiO2 / 2, R2SiO3 / 2, HSiO3 / 2 and SiO4 / 2 units, with the proviso that at least 2 units per molecule contain a silicon bonded hydrogen atom. In the preceding formulae, each R1and each R2are a monovalent hydrocarbyl groups as described above. Alternatively in this crosslinker, each R1may be alkyl such as methyl. Alternatively, in this crosslinker, each R2may be alkyl such as methyl or aryl such as phenyl. This organohydrogensiloxane crosslinker may be linear, branched, cyclic, resinous, or a combination thereof. Alternatively, the organohydrogensiloxane crosslinker may be linear or branched. Alternatively, the organohydrogensiloxane may be linear.

[0057] For example, the linear organohydrogensiloxane crosslinker may comprise an aryl- functional siloxane oligomer of unit formula (R1HSiOi / 2)2(R82SiO2 / 2)J, where each R1is the independently selected monovalent hydrocarbyl group of 1 to 30 carbon atoms, as described above; each R8is an independently selected aryl group of 6 to 30 carbon atoms as described above; and subscript] represents average number of disiloxy units per molecule, and subscript] is an integer with a value of 1 to 3. Alternatively, in this unit formula each R1may be alkyl such as methyl. Alternatively, in this unit formula each R8may be aryl such as phenyl. Subscript] may be 1, 2, or 3; alternatively 1 or 2, and alternatively j may be 1. The crosslinker, may be, for example l,L5,5-tetramethyl-3,3-diphenyltrisiloxane (CAS No. 17875-55-7) which is commercially available from Sigma Aldrich, Inc.

[0058] Alternatively, the organohydrogensiloxane crosslinker may be branched and may comprise an aryl-functional organohydrogensiloxane of unit formula (HR12SiOi / 2)k(R8SiO3 / 2)(i-k>, where subscript k represents a mole fraction and has a value of 0.5 to 0.7, alternatively 0.6, and R1and R8are as described above. This branched aryl-functional organohydrogensiloxane may have a weight average molecular weight of 700 g / mol to 1,000 g / mol, alternatively 750 g / mol to 950 g / mol. This branched organohydrogensiloxane crosslinker is exemplified by thecrosslinkers in US Patent Publication 20200291190 and by RMS-356 described in US Patent Publication 20210198450.

[0059] Starting material (c2) is a hydrosilylation reaction catalyst. The hydrosilylation reaction catalyst will promote a reaction between the alkenyl groups of the silsesquioxane resin and the silicon bonded hydrogen atoms of starting materials (a2- 1) and (a2-2), described above. The hydrosilylation reaction catalyst comprises a platinum group metal, and is as described and exemplified above. The amount of hydrosilylation reaction catalyst depends on various factors including the selections and SiH contents of starting materials (a2-l) and (a2-2), the alkenyl content of the silsesquioxane resin, and the hydrosilylation reaction conditions, such as temperature, however the amount may be sufficient to provide 0.1 to 5,000 ppm of platinum group metal, alternatively 1 to 1,000 ppm, alternatively 1 to 100 ppm, and alternatively 1 to 10 ppm, based on combined weights of the silsesquioxane resin and starting materials (a2-l) and (a2-2).

[0060] In step (A2) of the method described above, the silsesquioxane resin and starting materials (a2- 1 ), (a2-2), and (c2) and optionally an additional starting material selected from the group consisting of a solvent (to aid mixing) and a manganese ion source and a phenolic compound (each as described and exemplified above), or a combination thereof, may be combined in a reactor with heating to a temperature of 50 °C to 150 °C, alternatively 90 °C to 110 °C, optionally under anaerobic conditions. Typically, the silsesquioxane resin is used in an amount to provide a molar excess of alkenyl groups such that the resulting alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may have residual silicon bonded alkenyl groups, and does not contain unreacted SiH. Alternatively, starting material (a2- 1) may be reacted with the silsesquioxane resin until all of its SiH is reacted, thereby preparing a resin - linear intermediate and thereafter starting material (a2-2) may be reacted with the resin - linear intermediate. Typically, the hydrosilylation reaction is performed under anaerobic conditions (i.e., < 2% oxygen atmosphere) for safe handling of SiH functional starting material.

[0061] In step (A3) of the method described above, recovering the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer may be performed by any convenient means, such as stripping and / or distillation, optionally with reduced pressure. In any one or more of steps (Al), (A2), and (A3), a manganese ion source and a phenolic compound as described and exemplified above may be added to minimize reaction of the alkenyl ester - groups.Furthermore, one skilled in the art would recognize that various alkenyl ester - functional resin - linear polyorganosiloxane block copolymers, including those of unit formula (A) and / or unit formula (B) described above may be made by the methods described herein by varying the selection of starting materials. For example, the alkenyl-, aryl-, functional resin linearpolyorganosiloxane block copolymer prepared by the method of US Patent 9765192 to Horstman, et al. may have alkenyl groups on the monofunctional siloxy units, the difunctional silo y units, and / or the trifunctional siloxy units, and these copolymers may used as starting materials to make the alkenyl ester - functional resin - linear polyorganosiloxane block copolymers of the present invention. Alternatively, one skilled in the art would recognize that alkenyl ester - functional resin - linear polyorganosiloxane block copolymers as described herein may be made by known methods, such as those described, for example, in US Patent 9(545668 by varying appropriate starting materials, such as by using an alkenyl ester functional trialkoxysilane, as described above, in the process for making the resin - linear polyorganosiloxane block copolymer.II. Curable Composition and Preparation Method

[0062] The alkenyl ester - functional resin - linear polyorganosiloxane block copolymer described above is useful in curable compositions. For example, a curable composition may comprise: (I) the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer, and (II) a catalyst. The curable composition may optionally further comprise an additional starting material, which may be selected from the group consisting of: a solvent, an organosiloxane resin, a stabilizer, a phosphor, a moisture scavenger, a metal-ligand complex, a filler, and a combination of two or more thereof.

[0063] Suitable solvents are exemplified by the aromatic hydrocarbons described above (e.g., benzene, toluene, xylene, and combinations thereof). Alternatively, a polar solvent, such as that described in US Patent Publication US20160118555 paragraph

[0104] may be used. The optional additional organosiloxane resin may be, for example, a polyorganosilicate resin, or may be a resin used in preparation of the copolymer herein (such as the silsesquioxane resin made in step (Al) of the second method for making the copolymer, described above). Alternatively, the optional additional resin may comprise an unreacted alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer as described above for starting material (1-1) in the method described above. Suitable stabilizers include boron compounds exemplified by boronic acid comprising an aromatic group, which is optionally fluorinated, such as those disclosed in US Patent 9006356. Suitable phosphors are known in the art and are disclosed, for example, in US Patent 9175140 at col. 22, lines 1 to 57; in US Patent 9927703 at col. 6, lines 19-63; or in US Patent Publication US20160009866 at paragraphs

[0222] to

[0223] . The moisture scavenger may be an alkoxysilane, such as isobutyltriethoxysilane. Suitable moisture scavengers are disclosed in US Patent 9051436 at col. 28 line 59. Suitable metal - ligand complexes are as disclosed in US Patent 9175140 at col. 16, line 53-col. 20, line 57. Fillers are disclosed, for example, in US Patent 9175140 at col. 20 line 58-col. 21, line 67, and US Patent PublicationUS20160009866 at paragraphs 10217 ]-| 0221 ]. Alternatively, the filler may comprise nanoparticles, such as those disclosed in US Patent publication US20160118555 at paragraphs

[0132] to

[0139] .

[0064] The curable composition may be prepared by any convenient means. For example the curable composition may be prepared by a method comprising: mixing starting materials comprising (I) the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer and (II) the catalyst under ambient conditions, and if present, any of the optional additional starting materials described above. The method may further comprise preparing the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer by the method described above, before mixing said alkenyl ester - functional resin - linear polyorganosiloxane block copolymer with the other starting materials of the curable composition.Thermally Curable Composition

[0065] The curable composition described above may be a thermally curable composition, wherein (II) the catalyst comprises a peroxide compound or an inhibited arylborane Lewis acid. Examples of suitable peroxide compounds are known in the art and are commercially available, such as benzoyl peroxide; cumene peroxide; 4-monochlorobenzoyl peroxide; t-butylperoctoate; t-butyl peroxybenzoate, tert-butylperoxybenzoate, tert-butyl cumyl peroxide, tert-butyloxide 2,5- dimethyl-2,5-di-tert-butylperoxyhexane; 2,4-dichlorobenzoyl peroxide; di-tertbutylperoxy- diisopropyl benzene; l,l-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane; 2,5-di-tert- butylperoxyhexane-3,2,5-dimethyl-2,5-bis(tert-butylperoxy) hexane; dicumyl peroxide; di-t- butyl peroxide; t-butyl hydroperoxide; cumene hydroperoxide; di-t-amyl peroxide; and combinations thereof. Peroxide compounds such as benzoyl peroxide are commercially available from Sigma - Aldrich.

[0066] Suitable inhibited arylborane Lewis acids are known in the art and are disclosed, for example, in US Patent Publication 20220169855 at paragraphs

[0044] to

[0057] , which is hereby incorporated by reference. For example, the Lewis acid may comprise a triaryl borane, such as those having the formula:, wherein R9is independently in each occurrence selected from H, F, Cl and CF3. Alternatively, at least one R9, per molecule, is F orCF3. The arylborane Lewis acid may be inhibited with an amine. The selection of amine isimportant because it must complex with the Lewis acid at 23 °C to inhibit catalytic activity of the Lewis acid in a reaction composition at that temperature, yet must release the Lewis acid at an elevated temperature so as to rapidly (within 10 minutes or less, alternatively 5 minutes or less, alternatively one minute less) gel the reaction composition at 90 °C. Reaction compositions can be monitored at 23 °C and 90 °C to determine gel times. Alternatively, or additionally, one can characterize by differential scanning calorimetry the temperature at which the curing reaction exotherm occurs (Tpeak). The Tpeak value for a composition should increase relative to the Tpeak for an identical amine- free composition if the proper amine is present, but desirably remains below 130 °C, alternatively below 120 °C, alternatively below 110 °C so as to reflect dissociation sufficient to rapidly cure at 90 °C.

[0067] Amines have been reported as irreversibly complexing with Lewis acid catalysts, except for triaryl amines which are reported to not compromise Lewis acid catalysts. Without wishing to be bound by theory, having one or more conjugated moiety attached the nitrogen of an amine through a conjugated carbon, the conjugated moiety helps delocalize the free electrons of the amine and weaken it as a Lewis base. As a result, amines having at least one conjugated moiety attached to the nitrogen of the amine through a conjugated carbon complex with and block Lewis acid catalyst at 23 °C so as preclude gelling of a reaction composition at 23 °C in 4 hours or less, alternatively 8 hours or less, alternatively 10 hours or less, alternatively 12 hours less, while at the same time complexes weakly enough so as to release the Lewis acid catalyst upon heating to 90 °C so as to gel the composition in 10 minutes or less, alternatively 5 minutes or less, alternatively one minute or less.

[0068] To be a sufficiently weak Lewis base, the amines have at least one, alternatively at least two, and can have three conjugated moieties attached to the nitrogen of the amine through a conjugated carbon so that the free electron pair on the nitrogen can dissociate with the conjugated moiety and weaken the amine as a Lewis base. Alternatively, the conjugated moieties are aromatic moieties.

[0069] Triaryl amines have three aromatic conjugated moieties attached to the amine nitrogen each through a conjugated carbon. As a result, triaryl amines are examples of amines that optimally delocalize the nitrogen free electrons to create a weak Lewis base. Nonetheless, triaryl amines have been surprisingly discovered to have a blocking effect on Lewis acid catalysts at 23 °C and inhibit Lewis acid catalyzed reaction at 23 °C and are in scope of the broadest scope of the amines suitable for use in the catalyst used in the thermally curable composition described herein. Desirably, the amines used herein are stronger Lewis bases than triaryl amines in order to achieve greater blocking effect (hence, longer shelf stability) at 23 °C. In that regard, while the amine can have one, two or three conjugated moieties attached to the nitrogen of the aminethrough a conjugated carbon, it is desirable that the amine is other than a triaryl amine. Compositions described herein can be free of triarylamines.

[0070] The ability of a conjugated moiety to weaken the strength of the amine as a Lewis base is further tunable with substituent groups that can be attached to the conjugated moiety.Including electron withdrawing groups (such as halogens) on the conjugated moiety will further draw the nitrogen electrons into the delocalized conjugated system and weaken the strength of the amine as a Lewis base. Including electron donating groups on the conjugated moiety has the opposite effect and increases the resulting amine strength as a Lewis base relative to the same amine with the conjugated moiety without the electron donating group(s).

[0071] The amine needs to be strong enough to bind to and block the Lewis acid catalyst at 23 °C in order to achieve shelf stability. The amine will release the acid at lower temperatures if it is a weaker Lewis base than if it were a stronger Lewis base. Hence, selection of the moieties attached to the nitrogen of the amine can be selected to achieve shelf stability and reactivity at a desired temperature.

[0072] Suitable amines have the amine nitrogen that is not a member of an N=C-N linkage such as in amidines, guanidines, and N-methylimidazole. Desirably, the composition is free of amines having an N=C-N linkage. For example, the composition can be free of amidines and guanidines.

[0073] In general, the amine has the following formula: RnR12R13N; wherein each of R11, R12, and R13is independently selected from a group consisting of hydrogen, alkyl, substituted alkyl, and conjugated moieties; and wherein at least one of R11, R12and R13is a conjugated moiety connected to the nitrogen by a conjugated carbon. One, two or three of R11, R12and R13can be a conjugated moiety connected to the nitrogen by a conjugated carbon. Alternatively, the conjugated moiety may be an aromatic moiety.

[0074] Examples of suitable amines for use herein include any one or any combination of more than one amine selected from a group consisting of: aniline, 4-methylaniline, 4-fluoroaniline, 2- chloro-4-fluoroaniline, diphenylamine, diphenylmethylamine, triphenylamine, 1 -naphthylamine, 2-naphthylamine, 1 -aminoanthracene, 2-aminoanthracene, 9-aminoanthracene, -aminostyrene, 1,3,5-hexatrien-l-amine, N,N-dimethyl-l,3,5-hexatrien-l-amine, 3-amino-2-propenal and 4- amino-3-buten-2-one.

[0075] The concentration of amine is at least at a molar equivalent to the concentration of Lewis acid so as to be able to complex with and block all of the Lewis acid catalyst at 23 °C. The concentration of amine can exceed the molar concentration of Lewis acid catalyst, but may be present at a concentration of 110 mol% or less, alternatively 105 mol% or less, alternatively 103 mol% or less and alternatively 101 mol% or less while also being present at 100 mol% ormore relative to total moles of Lewis acid catalyst.

[0076] The amine and Lewis acid form a complex in the thermally curable composition that blocks the Lewis acid from catalyzing a reaction between the other composition components sufficiently to be shelf stable at 23 °C. Upon heating, the amine releases the Lewis acid to allow the Lewis acid to catalyze a reaction.

[0077] The amount of inhibited arylborane Lewis acid catalyst in the thermally curable composition may be > 100 ppm, alternatively at least 200 ppm, alternatively at least 300 ppm; while at the same time the amount may be up to 1,000 ppm, alternatively up to 750 ppm, alternatively up to 500 ppm, based on weight of the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer.UV Curable Composition

[0078] Alternatively, the curable composition described above may be a UV curable composition, wherein (II) the catalyst comprises a photoinitiator. Suitable photoinitiators include acetophenone; propiophenone; benzophenone; 2-hydroxy-2- methylpropiophenone; 2,2- dimethoxy- 1 ,2-diphenylethan- l-one; 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone; 1 -hydroxy cyclohexylphenylketone; l-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-l- propan- l-one; 2-hydroxy-l-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl- propan-l-one; 2-methyl-l-(4-methylthiophenyl)-2-morpholinopropan- l-one; 2-benzyl-2- dimethylamino-(4-morpholinophenyl)-butanone-l,2- (dimethylamino)-2-[(4- methylphenyl)methyl]-l-[4-(4-morpholinyl)phenyl]-l-butanone; 2,4,6- trimethylbenzoyldiphenyl-phosphine oxide; bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide;1,2-octanedione; l-[4-(phenylthio)- 2-(O-benzoyloxime)]ethanone; l-[9-ethyl-6-(2- methylbenzoyl)-9H-carbazol-3-yl]-l-(O-acetyloxime); ethyl-4-dimethylaminobenzoate; 2- ethylhexyl-4-dimethylaminobenzoate; bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl- pentylphosphine oxide; and combinations of two or more thereof. Photoinitiators are known in the art and are commercially available. For example, 1 -hydroxycyclohexylphenylketone is commercially available as IRGACURE™ 184 from BASF; and 2-benzyl-2-(dimethylamino)-4'- morpholinobutyrophenone is commercially available as IRGACURE™ 369 from BASF.Photoinitiators are disclosed, for example, in EP Patent Publication EP3885420A and US Patent US 10233322.III. Method of Use

[0079] The curable composition described above is useful for preparing an encapsulant, such as an optical encapsulant film. The curable composition, and cured product thereof, may be used, for example, in addition to, or instead of, the encapsulant and / or the resin - linear polyorganosiloxane block copolymer described in US Patents 8921493, 8921494, 9045668,9051436, 9076934, 9175140, 9181402, 9212262, 9705056, 9765192, 9927703, 10155885, and 11015025; US Patent Publications 20160009866, 20160032148, 20160118555, and 20170194539; and PCT Patent Publications W02013134018 and W02014002919. The curable composition may be used in a method comprising: 1) applying the curable composition described above to a substrate (such as that disclosed in any of the references cited above), optionally 2) removing solvent, when present, and 3) curing the composition. Curing the composition may be performed by any convenient means, such as heating when the catalyst comprises a peroxide compound, a Lewis acid or other thermal cure catalyst; or exposure to UV radiation when the catalyst comprises a photoinitiator.EXAMPLES

[0080] The following examples are provided to illustrate the invention to one skilled in the art and are not to be interpreted as limiting the scope of the invention set forth in the claims. The starting materials used in these examples are summarized below in Table 1.Table 1 - Starting Materials

[0081] In Table 1, above, MA Oligomer comprised the structure:

[0082] In this synthesis example 1 , a vinyl-functional resin - linear polyorganosiloxane block copolymer intermediate (TV1-RL) was prepared as follows: A 3L 4 neck round bottom flask was equipped with a thermocouple, Teflon stir paddle attached to a glass stir shaft, and a Dean Stark apparatus attached to a water-cooled condenser. The flask was loaded with: 217 Flake (270.00g, 1.977mols Si), toluene (722.31g) + an amount of toluene equal to the volume of the Dean Stark apparatus. A nitrogen blanket was applied. The flask was heated at reflux for 30 minutes to remove water from the 217 Flake. The flask was cooled to a couple of degrees below reflux and contained a resin solution.

[0083] Next, RL Coupling was performed as follows: A solution of toluene (177.69g) and Silanol Terminated PDMS (330.0g, 4.430mols Si) was capped with acetoxysilanes. The sample was prepared in a glove box (same day) under nitrogen by adding VTA (25.50g, 0.1098mols Si) and OFS-1579 (10.36g, 0.0456mols Si) to the Silanol Terminated PDMS and mixing at roomtemperature for 1 hour. Acetoxysilane capped PDMS solution was formed. The acetoxysilane capped PDMS solution was added to the above resin solution quickly. The resulting mixture was heated at reflux for 2 hours, and then left overnight at room temperature.

[0084] Next, Water Treatments 1 & 2 (each-20: 1 molar ratio, water: MTA / ETA + VTA) were performed. The following process was repeated two times: At ~90 °C added DI water (56.0g) and then removed water by azeotropic distillation, in which were distilled off 300 g of volatiles to increase the solids content up to ~50%.

[0085] Next, Water Treatments 3, 4 & 5 were performed. The following process was repeated three times: At ~90 °C added DI water (56.0 g), and thereafter removed water by azeotropic distillation. The resulting mixture was cooled to room temperature and then pressure filtered through a 142 mm diameter Magna, Nylon, Supported, Plain, 5.0 Micron filter to obtain TV1-R product.

[0086] The product was analyzed. The results showed product NVC films were clear, smooth, and flexible. Yield after filtration: 1153.7 g of solution =581.5 g solids. Estimated vinyl equivalent weight: 5537 g / mol vinyl (based on the assumption of all acetoxy groups hydrolyzing and condensing with silanols on resin and PDMS).

[0087] In this Synthesis Example 2, a methacryloxypropyl - functional resin - linear polyorganosiloxane block copolymer (sample 2-1) was prepared from the vinyl-functional resin - linear polyorganosiloxane block copolymer intermediate (TV1-RL) prepared as described above in synthesis example 1. The procedure was as follows: To a 500 ml 3 necked flask were added 100 g of the TV1-RL, 4.86 g MA Oligomer (as described above in Table 1), Karstedt’s catalyst in an amount sufficient to provide 5 ppm Pt, and 100 ml toluene under Nitrogen. The reaction mixture was heated to reflux for 5 hours while stirring under nitrogen. After cooling down, the reaction solution was concentrated by using a rotary evaporator under 100 °C / 6 mmHg. Finally 166 g concentrated liquid methacryloxypropyl - functional resin - linear polyorganosiloxane block copolymer product was obtained with NVC of 63%.

[0088] NMR spectra showed 95% of vinyl groups converted to methacryloxypropyl - functional groups of formula. A methacryloxypropyl - functional resin - linear polyorganosiloxane block copolymer was produced in this example. Three batches of methacryloxypropyl - functional resin - linear polyorganosiloxane blockcopolymer were prepared according to synthesis examples 1 and 2 by varying amounts of starting materials. These samples are summarized below in Table 2.Table 2 - Methacryloxypropyl - functional resin - linear polyorganosiloxane block copolymers of the present invention

[0089] In this synthesis example 3, inhibited BCF catalysts were prepared as follows:(1) Dissolve BCF in toluene as BCF stock solution (typically 5 weight % BCF in toluene);(2) Dissolve TEA (triethylamine) or DMA (dimethylaniline) in toluene as TEA / DMA stock solution (typically 5%);(3) Add a desired amount of TEA / DMA solution into the BCF stock solution to make 1 : 1 mol ratio of [BCF] / [TEA] or [BCF] / [DMA], and then sonicate the mixture for a couple of minutes;(4) Leave the resulting prepared catalyst solution still on bench or shelf overnight before use; (because without wishing to be bound by theory, it is thought that the binding of all TEA or DMA molecules to BCF requires at least a couple of hours).

[0090] The [BCF] / [TEA] produced as described above is shown below.

[0091] Above, the structures of BCF-TEA thermal latent catalyst and the released BCF, the formation of BCF-TEA complex at RT and the dissociation of the complex to release of BCF catalyst upon heating are shown.

[0092] The samples prepared as described above were tested for ability to cure via thermal and UV mechanisms, according to the thermal cure and UV cure test methods, respectively, described below. Additional test methods used in the examples herein are also described below.Test Methods

[0093] In this Thermal cure test method, formulations comprising a methacryloxypropyl - functional resin - linear polyorganosiloxane copolymer prepared according to synthesis example2 described above and an inhibited BCF catalyst prepared as described in synthesis example 3 were cured by thermal heating. Samples were dried at RT for 3 days and then cured for 30 min in 150 °C oven. The cure% of each cured film sample produced by this method was measured by the gel swelling test described below.

[0094] The gel swelling tested (cure%) referenced above was performed by (1) immersing each cured film sample in toluene for 45 minutes, (2) drying the sample in 150 °C oven for 2 hours, and (3) measuring the weight loss to decide the cure% (the cure% = Wd / Wo, Wd: the weight of the dried sample after immersing in toluene and drying at 150 °C, Wo: the weight of the original cured sample). The cure degree was not acceptable if the cure% < 80%.

[0095] Analysis of samples described above by29Si NMR was performed as follows: 5 g of a alkenyl ester - functional resin - linear polyorganosiloxane block copolymer as described above was mixed with 1 ml De-benzene for NMR characterization. The29Si NMR spectra of each product were collected by a Bruker 600 MHz NMR instrument (NS = 256, dl = 60).

[0096] Analysis of samples described above by GPC was performed as follows: Samples were prepared in certified ACS grade toluene at 1 % concentration, filtered through a 0.45 um PTFE syringe filter, and analyzed against polystyrene standards. The relative calibration (3rdorder fit) used for molecular weight determination was based on 12 polystyrene standards ranging in molecular weights from 580 to 906,600 Daltons. The chromatographic apparatus was a Viscotek GPC Max equipped with a vacuum degasser, a Viscotek VE358O RI detector and two (300 mm x 7.5 mm) Polymer Laboratories mixed C columns (molecular weight separation range of 200 to 3,000,000) preceded by a guard column. Separations were performed using certified grade THF programmed to flow at 1.0 ml / min, injection volume was set at 100 uL and columns and detector were heated at 35 °C. Data collection was 45 minutes and processing was performed using OmniSEC 4.7.0 software.

[0097] Tensile analysis according to CTM 0137A, ASTM D412 was performed as follows: 1 mm thick films for each alkenyl ester - functional resin - linear polyorganosiloxane block copolymer composition were prepared in a Teflon coated Al pan, followed by either thermal cure or UV cure according to the test methods described above. Dog-bone shaped specimens were die cut from the cured films typically. Specimens were tested at ambient temperature and humidity with an Instron universal test machine utilizing Bluehill 2 software. Test speed used was 2 inch / min, and specimens were pulled to failure. Median elongation and tensile strength, at both peak and breaking point, were reported along with Young’s modulus. Raw stress-strain strain curves were also exported for further analysis and comparison with other materials.

[0098] Adhesion testing was performed as follows: The adhesion data for each sample were measured according to ASTM method D3359 by using a Gardco PA-2000 adhesion test kit aftercure (according to the thermal cure or LJV cure test method described above) and aging. After scratching the film surface by using a Crosshatch tool, the amount of the coating materials remained on the Al panel surface indicated the adhesion capability of the film. The higher the remained%, the stronger the adhesion of the materials to the substrate. The adhesion was not acceptable if the amount that remained was < 80%.

[0099] Color testing for CIE B* value was performed on the cured films prepared according to the thermal cure or UV cure test method described above. CIE b* values of samples were measured by using B YK color meter. 1 x3 cm2samples were cut from ~1 mm thick cured film, followed by aging at 150 °C for 5 days and then measuring b* values by using BYK color meter. The discoloration was not acceptable if b* value was > 5.Thermally Curing alkenyl ester - functional Resin - Linear Polyorganosiloxane Block Copolymers (MA-RLs)

[0100] Table 3, below, summarizes several examples of thermally cured MA-RLs. They were cured thermally by using either (1) benzoyl peroxide (BPO, examples 3 and 5) or (2) tri(pentafluorophenyl)borane (examples 1,2 and 4), BCF or B(CeF5)3, as catalysts. Cl and C2 are two comparative examples which are vinyl functional resin - linear polyorganosiloxane block copolymers (TV|-RL prepared according to Synthesis Example 1) and cured by Pt catalyzed hydrosilylation reaction. C3 is a comparative example comprising physically blended methacryl (MA) - functional TPhresin and MA - functional PDMS polymer. BPO is a typical thermal initiator for free radical polymerization of acrylate groups. MA-RLs of examples 3 and 5 are formulated with 1 % BPO, followed by curing at 150 °C for 1 h.

[0101] BCF was reported to catalyze the group transfer polymerization (GTP) of acrylates with assistant of small amount SiH containing molecules (e.g., 2-10 mol% MHO.4TQ.6 used here). Trialkyl or triaryl amines were used as inhibitors to control the catalytic activity of BCF catalysts. In Table 3, BCF-DMA (DMA: dimethylaniline) or BCF-TEA complex prepared according to synthesis example 3 was used as the thermal latent catalyst, which can inhibit the polymerization of acrylates at room temperature (RT) but release BCF to activate the polymerization at elevated temperature. The ratio of [BCF] to [DMA] was 1:2 for samples 1 and 2, and that of [BCF] to [TEA] was 1:1 for sample 4. MA-RLs of samples 1, 2 and 4 were formulated with 2-10 mol% MHo.4To.6 and BCF-DMA or BCF-TEA complex (with 500 ppm BCF loading). DMA or TEA binds to the electron deficient Boron center of BCF at RT to inhibit the catalytic activity of BCF, but upon heating to certain temperature, this catalyst complex can dissociate and release BCF as the active catalyst to catalyze the polymerization cure of MA-RLs.

[0102] Table 3 displays the data measured for thermally cured MA-RLs. Each composition was mixed by SpeedMixer and poured into a Teflon coated Al pan or PET films to make thinfilm (100-1000 pm), and left at room temperature (RT) in hood over 5 days to dry / remove the remained solvent toluene, and then put in 150 °C oven for 1 hour to cure. The cure% for each sample was measured by using gel swelling test described above. The gel swelling test indicated that (1) all examples catalyzed by either BCF or BPO cured well (most cure% > 90%); (2) all examples (1 to 5) show more than 7 days shelf life at room temperature because the uncured samples completely dissolved in toluene in 30 min; (3) comparative example C2 (was physically blended MA-functional TPhresin and MA-terminated PDMS polymer) did not cure well (the cure% < 50%) because of the incompatibility.

[0103] The adhesion data in Table 3 were measured by Crosshatch Adhesion Test on F4 board or Al plate. The higher the remained%, the stronger the adhesion of the materials to substrates.Compared with the comparative hydrosilylation curable sample Cl, MA-RL composition(samples 1-5 in Table 3) showed much stronger adhesion (100% film materials remained on the substrates). The b* value for each sample was measured by using BYK Spectra-Guide Colormeter before and after thermal aging. The cured MA-RLs were highly thermal stable because they were still tough and flexible after thermal aging for 5 days at 150 °C and showed low discoloration with slightly changed b* values before and after thermal aging.

[0104] Comparative example C2 was a physically blended mixture of MA-functional TPhresin (TMAo.2sTPho.75 described above in Table 1) and MA-terminated PDMS polymer (MMADIOOMMA). C2 was very hazy before and after cure. The gel swelling test showed the cure% of C2 was 47%. The haze and low cure% of C2 were caused by the incompatibility between phenyl-T resin andMA - terminated PDMS polymer. The working examples and comparative example 2 show the advantages of this invention (i.e., alkenyl ester - functional resin - linear polyorganosiloxane block copolymers) over the physically mixed blends of methacrylate functional linear polydiorganosiloxanes and methacrylate functional silsesquioxane resins.Table 3: Data measured for thermally cured MA-RL. Cure conditions for all samples: 150 °C for 1 hour. Shelf life at room temperature: > 7 days for each sample.UV Curing MA-RLs by Photoinitiators

[0105] Free radical polymerization of MA-RLs can be initiated by photoinitiators with UV irradiation. IRGACURE-369 (IRG-369) and IRGACURE-184 (IRG-184) were used as photoinitiators for UV curing the developed MA-RLs. Several compositions in Table 4 were developed to test the UV cure efficiency and the thermal stability of the UV cured MA-RL copolymers.Table 4: Data measured for UV cured MA-RLs. All examples cured by 10 second irradiation of 365 nm LED UV light with UV power of 2 J / cm2. Cure% was measured by gel swelling test.i i i |

[0106] Table 4 shows the data measured for UV cured MA-RLs (examples 6-9). All samples comprise MA-RL (2a, 2b, or 2c) and photoinitiator (either IRG-369 or IRG-184). Each sample was coated as films on Teflon coated Al or PET substrates with thickness from 100 to 1000 pm, dried at 70 °C for 30 min or at RT for 5 days to remove the solvent toluene. The UV cure was done by irradiating samples with 365 nm UV LED light with desired UV power (2 J / cm2) for 10 seconds (except sample 9 using broad band UV light with wavelength from 200 to 450 nm). Gel swelling test indicated that (1) all MA-RL examples cured well with 2J / cm2UV power showing more than 85% cure; (2) MA-RLs showed much better UV cure than hydrosilylation curable TV1RL (C3); (3) IRG-369 provided a little better cure than IRG-184 but resulted in more yellowing of samples; (4) all samples (6-9) showed more than 7 days shelf life at room temperature and under darkness; (5) comparative example C4 (physically blended MA- functional TPhresin and MA-terminated PDMS polymer) did not cure well (51% cure).

[0107] Although IRG-369 was a more active photoinitiator, it brought more yellow color to the cured MA-RLs than IRG-184 did under the conditions tested. Samples 6 and 7 with 0.5% IRG-369 loading made the b* value of the cured MA-RL samples up to 17.8, but samples 8 and 9 with 1% IRG-184 showed very low b* value even after thermal aging at 150 °C for 5 days. The UV cured MA-RL samples with IRG-184 were still tough and flexible after thermally aging. Similar to thermally cured MA-RLs, UV cured MA-RLs also showed much stronger adhesion on either plastic or Al substrate than hydrosilylation curable TV1RL (comparative example C3). Comparative example C4, physically blended TMAo.2sTPho,75 resin and linear polymer MMADIOOMMA, was very hazy and showed low cure% (51%) after UV irradiation, which furtherindicated the advantages of the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer herein over the only physically blended mixture in comparative example C4.

[0108] Mechanical properties of cured MA-RLs are shown below in Table 5.Table 5: Mechanical properties and thermal stability of cured MA-RLs before and after aging at 150 °C for 5 days. Sample 10 used BCF-DMA, and sample 11 used BCF-TEA, as thermal cure catalysts. Sample 12 used 0.5 % IRG-369 as photoinitiator and sample 13 used 1 % TRG-184 as photo-initiators and 200-450 nm UV lamp for UV cure (4J / cm2).

[0109] Table 5 shows the mechanical properties and thermal stability of the cured MA-RLs. Samples 10 and 11 used BCF-DMA and BCF-TEA as catalysts, respectively, and were thermally cured at 150 °C for 1 hour. Samples 12 and 13 used IRG-369 and IRG-184 as photoinitiators, respectively, and were cured by UV irradiation with 2J / cm2power and 200-450 nm UV wavelength. Each sample was prepared as a 0.8 mm thick cured film, cut as dog-bone shaped samples and aged at 150 °C for 5 days. Tensile testing was done for each sample before and after thermal aging. All cured MA-RL examples showed high thermal stability indicated by the slightly changed Young’s modulus (YM) and the remaining high elongation %. Especially for IRG-184 cured sample 13, both Young’s modulus and Elongation% exhibited minimal change.PROBLEMS TO BE ADDRESSED

[0110] Development of LED lighting continuously requires encapsulants which have high transparency, high thermal and / or photothermal stability, strong adhesion, excellent mechanical properties, fast cure, and low cost. Especially fast cure at RT or under UV is highly desirable considering the sustainability and energy savings. The current hydrosilylation and condensation cure systems were found to have limitations as far as inhibition and poisons that can inhibit or prevent cure. For example, hydrosilylation curable silicone release coating products may show slow cure speed and poor adhesion on thermal paper substrates because the additives (e.g., thiol and amine) in the top coating layer of thermal paper act as poisons for the Pt based hydrosilylation catalyst.SOLUTION

[0111] The present inventors found that grafting alkenyl ester - functional groups onto resin -linear polyorganosiloxane block copolymers provided unique alkenyl ester - functional resin - linear polyorganosiloxane block copolymers with benefits from both alkenyl ester groups and polyorganosiloxanes without compromising either one. Benefits may include one or more of improved adhesion, high hardness and fast cure (especially fast UV cure) from the alkenyl ester functionality and high thermal and / or photothermal stability and flexibility from the polyorganosiloxane functionality. In addition, alkenyl ester as a cure moiety does not suffer from the same inhibition as hydrosilylation and does not generate moisture as a side product as condensation reaction.DEFINITIONS AND USAGE OF TERMS

[0112] All amounts, ratios, and percentages are by weight unless otherwise indicated by the context of the specification. The articles ‘a’, ‘an’, and ‘the’ each refer to one or more, unless otherwise indicated by the context of specification. The singular includes the plural unless otherwise indicated by the context of the specification. The SUMMARY and ABSTRACT are hereby incorporated by reference. The amounts of all starting materials in a composition total 100%. The transitional phrases “comprising”, “consisting essentially of’, and “consisting of’ are used as described in the Manual of Patent Examining Procedure Ninth Edition, Revision 08.2017, Last Revised January 2018 at section §2111.03 I., II., and III. The use of “for example,” “e.g. ” “such as,” and “including” to list illustrative examples does not limit to only the listed examples. Thus, “for example” or “such as” means “for example, but not limited to” or “such as, but not limited to” and encompasses other similar or equivalent examples. The disclosure of ranges includes the range itself and also anything subsumed therein, as well as endpoints. Similarly, the disclosure of Markush groups includes the entire group and also any individual members and subgroups subsumed therein. For example, disclosure of the Markush group a hydrogen atom, an alkyl group, an alkenyl group, or an aryl group, includes the member alkyl individually; the subgroup alkyl and aryl; and any other individual member and subgroup subsumed therein. Any feature or aspect of the invention may be used in combination with any other feature or aspect recited herein. Abbreviations are as defined below in Table 6.Table 6 - Abbreviations

Claims

CLAIMS:

1. An alkenyl ester - functional resin - linear polyorganosiloxane block copolymer, wherein the copolymer comprises linear blocks and non - linear blocks, wherein each linear block independently comprises 10 to 400 disiloxy units of formula (R22SiO2 / 2), wherein each R2is an independently selected monovalent hydrocarbyl group of 1 to 30 carbon atoms; each non - linear block has a molecular weight of at least 500 g / mol, the non - linear blocks comprise trisiloxy units and hydrolyzable groups, and wherein the non - linear blocks further comprise alkenyl ester - functional groups bonded to silicon atoms; at least 30 mol % of the non - linear blocks are crosslinked with each other, each linear block is linked to at least one non - linear block, and the copolymer has a weight average molecular weight of at least 20,000 g / mol measured by gel permeation chromatography.

2. The copolymer of claim 1, wherein the copolymer comprises unit formula (A), unit formula (B), or both, wherein: unit formula (A) comprises: ((R3SiO3 / 2)d(R4SiO3 / 2)e(ZO1 / 2)f;wherein each R1is an independently selected monovalent hydrocarbyl group of 1 to 30 carbon atoms; each R2is an independently selected monovalent hydrocarbyl group of 1 to 30 carbon atoms; each D1is an independently selected divalent hydrocarbyl group of 2 to 30 carbon atoms;each R3is independently selected from an alkenyl group of 2 to 30 carbon atoms and an aryl group of 6 to 30 carbon atoms; each R4is a alkenyl ester - functional group; each Z is independently selected from H or a monovalent hydrocarbyl group of 1 to 30 carbon atoms; subscripts a, b, c, d, and e represent mole fractions of each siloxy unit in unit formula(A), and have values such that0<a<0.1;0.3 <b <0.8;0<c<0.2;0.3 <(b + c)<0.8;0.1 <d<0.7;0.035 < e < 0.285; a quantity (a + b + c + d + e) = 1 ; subscript f represents a molar amount of hydrolyzable groups in the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer of unit formula (A), and subscript f has a value such that 0 < f < 0.

5. subscripts m, n, o, p, and q represent mole fractions of each siloxy unit in unit formula(B), and have values such that0<m<0.1;0.3<n<0.8;0.035 <o <0.285;0.3 < (n + o) < 0.8;0.035 <p <0.285;0.1 <q <0.7;0.035 < r < 0.285; a quantity (m + n + o + p + q + r) = 1; subscript s represents a molar amount of hydrolyzable groups in the copolymer, and subscript s has a value such that 0 < s < 0.5.

3. The copolymer of claim 1 or claim 2, wherein the alkenyl ester - functional groups each have formulaD2is a divalent hydrocarbyl group of 2 to 30 carbon atoms, andR10is H or an alkyl group of 1 to 6 carbon atoms.

4. The copolymer of claim 3, wherein the alkenyl ester - functional group is selected from an acryloxyalkyl- group or a methacryloxy alkyl- group.

5. The copolymer of claim 3, where the alkenyl ester - functional group is selected from acryloxymethyl, methacryloxymethyl, acryloxypropyl, methacryloxypropyl, acryloxybutyl, or methacryloxybutyl.

6. A method for making the copolymer of any one of claims 1 to 5, wherein the method comprises:(1) combining, under conditions to effect hydrosilylation reaction, starting materials comprising (1-1) an alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer comprising difunctional siloxy units primarily bonded together to form linear blocks of polymeric polydiorganosiloxane chains having 10 to 400 units per linear block and trifunctional siloxy units primarily bonded to each other to form non - linear blocks, wherein each non - linear block has a molecular weight of at least 500 g / mol measured by gel permeation chromatography, and wherein at least 30% of the non - linear blocks are crosslinked with each other, and wherein the alkenyl-, aryl- functional resin - linear polyorganosiloxane block copolymer may have a Mw of 20,000 g / mol to 500,000 g / mol; and(1-2) an alkenyl ester- functional silyl hydride compound of formula, wherein each R16is an independently selected monovalent hydrocarbyl group of 1 to 30 carbon atoms,R4is the alkenyl ester - functional group, and subscript w is an integer with a value of 0, 1, or 2; and (c2) a hydrosilylation reaction catalyst; and7. A method for making the copolymer of any one of claims 1 to 5, wherein the method comprises:(Al) combining, under conditions to effect hydrolysis reaction, starting materials comprising:(a 1 - 1 ) an aryltrialkoxysilane of formula R6Si(OR5)3, where R6is an aryl group of6 to 30 carbon atoms, and each R5is an independently selected alkyl group of 1 to 6 carbon atoms;(al-2) an alkenyl ester - functional trialkoxysilane of formula R4Si(OR5)3, wherein R4is the alkenyl ester - functional group described and exemplified above, and each R5is the independently selected alkyl group of 1 to 6 carbon atoms;(a 1-3) a bis-alkenyl-terminated diorganosiloxane oligomer of unit formula (R7RI2SiOi / 2)2(R22SiO2 / 2)g, where R1and R2are the monovalent hydrocarbyl groups of 1 to 30 carbon atoms as described above; subscript g represents an average number of disiloxy units per molecule, and subscript g is an integer with value such that g > 0; and each R7is an independently selected alkenyl group of 2 to 30 carbon atoms; and(al-4) water; in the presence of (cl) an acid catalyst, thereby forming a hydrolysis product comprising an aryl-, alkenyl ester-, alkenyl- functional silsesquioxane (MT) resin; and optionally adding a solvent to the hydrolysis product formed in step (Al); optionally neutralizing (cl) the acid catalyst after step (Al);(A2) combining, under conditions to effect hydrosilylation reaction, starting materials comprising(a) the aryl-, alkenyl ester-, alkenyl- functional silsesquioxane resin prepared in step (Al),(a2-l) a linear polyorganohydrogensiloxane of unit formula (R]2HSiOi / 2)2(R22SiO2 / 2)h, where each R1and each R2are the independently selected monovalent hydrocarbyl groups of 1 to 30 carbon atoms, subscript h represents an average number of disiloxy units per molecule, and subscript h is an integer with a value of 8 to 398; and(a2-2) an organohydrogensiloxane crosslinker; in the presence of (c2) a hydrosilylation reaction catalyst, thereby forming a hydrosilylation reaction product comprising the copolymer; and optionally (A3) recovering the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer from the hydrosilylation reaction product.

8. The method of claim 6 or claim 7, wherein an additional starting material is used in the method, and the additional starting material is selected from a solvent or an inhibitor or both.

9. The method of claim 8, wherein the method comprises heating the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer under anaerobic conditions; the inhibitor is present; and the inhibitor comprises a manganese ion source and a phenolic compound.

10. A curable composition comprising:(I) an alkenyl ester - functional resin - linear polyorganosiloxane block copolymer according to any one of claims 1 to 5, and(II) a catalyst.

11. The curable composition of claim 10, wherein the composition is thermally curable, and wherein (II) the catalyst comprises a peroxide compound or an inhibited fluorinated arylborane Lewis acid.

12. The curable composition of claim 10, wherein the composition is UV curable, and wherein the catalyst comprises a photoinitiator.

13. The curable composition of any one of claims 10 to 12, further comprising an additional starting material selected from the group consisting of: a solvent, an organosiloxane resin, a stabilizer, a phosphor, a moisture scavenger, a metal-ligand complex, a filler, and a combination of two or more thereof.

14. A method for preparing the composition of any one of claims 10 to 13, wherein the method comprises: mixing starting materials comprising the alkenyl ester - functional resin - linear polyorganosiloxane block copolymer and the catalyst under ambient conditions.

15. A method comprising:1) applying the composition of any one of claims 10 to 13 to a substrate, and optionally 2) removing solvent, when present, and3) curing the composition.

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